1Appendix D

2Water Framework Directive Assessment

3Water Framework Directive Compliance Assessment

This Appendix reports on a high level assessment to determine the compliance of the developing Local Flood Risk Management Strategy (LFRMS) with the Water Framework Directive (Directive 2000/60/EC of 23 October 2000 establishing a framework for Community action in the field of water policy) (WFD). It:

  1. Describes the relevant objectives of the WFD;
  2. Describes the relevant baseline conditions for water bodies in the Westminster LFRMS study area;
  3. Identifies the consequences of the proposed strategic objectives for the water bodies;
  4. Identifies opportunities that might be taken to improve water bodies as the LFRMS is implemented.

The Water Framework Directive

Background

The WFD was implemented in England by The Water Environment (Water Framework Directive) (England and Wales) Regulations 2003. It combines water quantity and water quality issues in an integrated approach to themanagement of all water bodies at the river basin level. Water bodies include rivers, lakes, estuaries (“transitional” water bodies), coastal waters and groundwater. The WFD effectively supersedes all EU environmental water-related legislation such as the Fisheries and Dangerous Substances Directives, and now drives the existing licensing and consenting framework in England.

The Directive sets out a framework for each Member State to establish River Basin Districts (RBD), for each of which a River Basin Management Plan (RBMP) must be developed and delivered. Each RBMPsets out the objectives for the waterbodies within it. Westminster is located in the Thames RBD. The overall requirement of the Directive is that all water bodies must achieve “good ecologicalstatus” or better by 2015 unless there are grounds for derogation. This status is determined by comparison with reference water bodies which are not impacted by human activities.

The ecological status of a water body is expressed in terms of five status classes (high, good, moderate, poor or bad). It is determined by assessing its biology, physio-chemical conditions and hydromorphology. In brief, the overall status is assessed as follows:

  • The biological assessment criteria uses numeric measures of communities of plants andanimals (fish, invertebrates, plants and algae);
  • The physio-chemical assessment uses measures such asdissolved oxygen and nutrient levels, which support the biological communities;
  • Thehydromorphological assessment uses measures related to water flow, sediment composition and movement,continuity (in rivers) and the structure and condition of habitats.

The overall ecological status of awaterbody is determined by whichever of these criteria is assessed to be the poorest. Forexample, if a water body achieves “good status” for each of physio-chemicalassessment and hydromorphological assessment, but only achieves “moderate status” for biological assessment, it would beclassed overall as having “moderate ecological status”.

Additionally some water bodies can be identified by the competent authority as requiring chemical assessment, which relates to the presence of potentially polluting chemicals. In this case assessment is based on the concentrations of a range of potentially polluting chemicals(e.g. certain pesticides and industrial chemicals) which are identified in the Annexes to the Directive. The WFD requires that such water bodies should also be of “good chemical status”.

For water bodies which are artificial (e.g. canals and reservoirs) or which are heavily modified by legitimate human activity such as flood defence or navigation the overall requirement is “good ecological potential”, recognising that a fully natural condition is not achievable. Ecological potential means that thewaterbody is managed to support the biology that can be achieved given its modifiedcondition. The quality status of HMWBs is classified by:

  • Identifying the impacts of physical modifications to the water body;
  • Identifying mitigation measures necessary to ensure the hydromorphologicalcharacteristics of the water body are consistent with good ecologicalpotential; and
  • Assessing whether those measures have been taken.

WFD Environmental Objectives

The WFD sets out a number of environmental objectives against which plans and projects should be assessed, as follows:

  • WFD1 - No changes affecting high status sites;
  • WFD2 - No changes that will cause failure to meet surface water good ecological status / potential or that will result in a deterioration of surface water ecological status / potential;
  • WFD3 - No changes which will permanently prevent or compromise theenvironmental objectives being met in other waterbodies;
  • WFD4 - No changes that will cause failure to meet good groundwater status orresult in deterioration in groundwater status.

It should be noted that WFD references to “surface waters” encompass river, lake, transitional, coastal and artificial water bodies, as distinct from urban surface drainage / runoff.

There is also a duty to enhance and restore water bodies where possible.

In order to meet these objectives, any activity which has the potential to have an impact on any of the quality elements (biological, physio chemical, hydromorphological or chemical) must be assessed. The Westminster LFRMS actions therefore need to be considered to ensure there are nofuture failures in meeting the WFD’s environmental objectives, or if any failures do occur,to ensure that they are defensible and therefore derogation would be legitimate.

The WFD also requires that any area(s) of water that is (are) designated under any other European Union directive meets the environmental requirements of that directive. This relates in particular to the Habitats Directive, Birds Directive, Nitrates Directive and Urban Wastewater Treatment Directive. (Previously the Freshwater Fish Directive and Shellfish Waters Directive were also relevant, but these are now superseded by the WFD.) This assessment considers the relevance of the Westminster LFRMSto such designations.

Assessment Methodology

The Environment Agency is the competent authority in England responsible for delivering the WFD. This assessment uses a methodology set out in Assessing new modifications for compliance with WFD: detailed supplementary guidance (Environment Agency, 2010), which can be summarised for the WestminsterLFRMS as:

  • Step 1: collate water body baseline data. All surface water bodies within or adjoining the LFRMS study area have been identified. There is no underlying groundwater body. The water bodies are shown in Figure 1 at the end of this report. Water bodies were identified through examination of the Environment Agency’s on-line water body mapping resources. For each water body the following information was collated: (i) WFD water body identification and classification; (ii) relevant WFD environmental objectives; (iii) relevant WFD actions from the Thames RBMP.
  • Step 2: collate LFRMS baseline data. Details on the options appraisal process and the selection of the preferred strategic options for the LFRMS are provided in the SEA Environmental Report and are not repeated here. The LFRMS draft actions are summarised.
  • Step 3: preliminary assessment. This assessment is the preliminary WFD assessmentfor the proposed actions to determine whether any might conflict with the WFD’s objectives.
  • Step 4: design and options appraisal. This assessment identifies where WFD objectives may need to be considered during future development of any of the proposed actions in the LFRMS, including identification of any mitigation measures that might be needed at scheme development stage following adoption of the strategy.
  • Step 5: detailed impact assessment. This step relates to the detailed design stage of a scheme, rather than to high level assessment of a strategy, so has not yet been undertaken.
  • Step 6: Article 4.7 tests. Again, this step relates to the detailed design stage of a scheme; however, this assessment does identify whether any LFRMS proposals are likely to result in any schemes which could require such an assessment in the future.
  • Step 7:reporting. This appendix to the SEA Environmental Report summarises the WFD preliminary assessment.
  • Step 8: post-project appraisal work. This relates to the delivery of future schemes following adoption of the strategy.

This process is outlined in Figure 2.

Figure 2: Outline of the WFD Assessment Process

Water Body Baseline Data (WFD Step 1)

The only WFD water bodies partially within the City of Westminster are:

  • Thames Middle (i.d. GB530603911402), which is estuarine and is considered to be heavily modified by flood protection and navigation such that it does not meet the WFD target of good ecological potential; and
  • Part of the Grand Union Canal (Grand Union Canal, Uxbridge to Hanwell Locks, Slough Arm, Paddington Arm, Regents Canal up i.d. GB70610078), an artificial water body that already meets the target of good potential.

Their extents within the City of Westminster are shown in Figure 1 at the end of this report.

The other significant surface water features in the City of Westminster (the Serpentine, Kensington Gardens Lake, Regent’s Park Lake, St James Park Lake, River Westbourne, Tyburn River and Tyburn Brook) are not identified by the Thames RBMP as water bodies in their own right.

The River Westbourne runs approximately north-south, entering the City of Westminster at Paddington/Bayswater, passing under Hyde Park then the western edge of the study area to enter the Thames near Chelsea Bridge. It has a small tributary, Tyburn Brook, under Hyde Park. The separate Tyburn River runs approximately north-south further eastwards within the study area, passing under Hyde Park and Green Park and entering the Thames near Vauxhall Bridge. There are no open stretches of the River Westbourne (which is enclosed as the “Ranelagh Sewer”) or Tyburn River (“King’s Scholars Pond Sewer”). However, taking a precautionary approach that minor tributaries should be considered as part of the river water body into which they flow, they should be considered as part of the Thames Middle water body.

Thames Middle GB530603911402

“Thames Middle” is a transitional water body and encompasses the tidal Thames from just upstream of Battersea Bridge downstream to Mucking. The Westminster LFRMS is therefore relevant to only a very small part of the water body, on the left (northern) bank (see Figure 1 at the end of this report). This is considered to be a heavily modified water body (HMWB) due to coastal protection, flood protection and navigation. There are several HMWB mitigation measures in place, mostly related to navigation, but some that are not, related to flood protection (see Table 1). Because not all the mitigation measures are in place, the water body is only at moderate ecological potential, with the objective of achieving good potential by 2027. Additionally the existing combination of tidal regime and freshwater flow does not support good status in the water body.

Considering the biological quality elements, invertebrates are moderate status, macroalgae are high status and fish and plants not reported.

Considering the supporting physio-chemical quality elements, these all support high status except for dissolved inorganic nitrogen and dissolved oxygen, which both support only moderate status.

The water body haselevated levels of certain pollutants, resulting in only moderate chemical status. The pollutants in question are: specific polycyclic aromatic hydrocarbons (i.e. benzo(ghi)perylene andindeno(123-cd)pyrene which are often indicators of industrial or fossil fuel related contamination); diuron which is an agricultural herbicide;and tributyltin compounds which were used in antifouling paintsbut are now discontinued. Each of these is persistent in the aquatic environment.

The water body has extents that are also designated under the Birds Directive, although these are towards its downstream end far removed from the City of Westminster. It is also designated under the Urban Wastewater Treatment Directive and the Nitrates Directive.

Table 1: Mitigation Measures for the Thames Middle Water Body

Mitigation Measure (from Thames RBMP) / In Place?
Vessel Management;
Modify vessel design;
Manage disturbance;
Site selection (dredged material disposal) (e.g. avoid sensitive sites);
Sediment management;
Alter timing of dredging / disposal;
Reduce sediment resuspension;
Reduce impact of dredging;
Prepare a dredging / disposal strategy;
Avoid the need to dredge (e.g. minimise under-keel clearance; use fluid mud navigation; flow
manipulation or training works) / Yes
Indirect / offsite mitigation (offsetting measures) / No
Operational and structural changes to locks, sluices, weirs, beach control, etc / No
Preserve and where possible enhance ecological value of marginal aquatic habitat, banks and
riparian zone / No
Managed realignment of flood defence / No
Remove obsolete structure / No

Grand Union Canal, Uxbridge to Hanwell Locks, Slough Arm, Paddington Arm, Regents Canal up GB70610078

This is an artificial water body (navigation)that includes part of the Regents Canal at Primrose Hill and the Grand Union Canal as far west as Cowley (Uxbridge), plus the Slough and Brentwood arms of the Grand Union Canal. Again, the Westminster LFRMS is relevant to only a very small part of the water body, where the Grand Union Canal and the Regents Canal cross the northern part of the study area (see Figure 1 at the end of this report).

All of the morphological mitigation measures for the water body are in place;as would be expected for a canal these all relate to navigation(see Table 2). There is no biological quality data used for the water body’s assessment, but because all the identified morphological mitigation measures are in place the water body is considered to be at good ecological potential.

Chemical status does not require assessment.

The water body has extents that are also designated under the Nitrates Directive.

Table 2: Mitigation Measures for the “Canal” Water Body

Mitigation Measure (from Thames RBMP) / In Place?
Manage disturbance;
Preserve and where possible enhance ecological value of marginal aquatic habitat, banks and riparian zone;
Avoid the need to dredge (e.g. minimise under-keel clearance; use fluid mud navigation; flow
manipulation or training works);
Prepare a dredging / disposal strategy;
Reduce impact of dredging;
Reduce sediment resuspension;
Alter timing of dredging / disposal;
Bank rehabilitation / reprofiling;
Site selection (dredged material disposal) (e.g. avoid sensitive sites);
Awareness raising / information boards (boat wash / sources of fine sediment);
Phased de-watering and other techniques;
Selective vegetation control regime;
Appropriate vegetation control technique;
Appropriate timing (vegetation control);
Appropriate techniques (invasive species);
Modify vessel design;
Vessel Management;
Sediment management. / Yes

Westminster LFRMS Baseline Data (WFD Step 2)

Development of the LFRMS is described in the main SEA Environmental Report and that information is not repeatedhere. Table 3 summarises the draft actions that are the subject of this WFD assessment.

Only those measures that could physically affect the water environment (directly or as a result of implementing policies) need to be taken through the WFD assessment process and these have been identified in bold blue font.

Table 3: Westminster LFRMS Draft Actions

LFRMS 1 Actions: Tackling sources of flooding from highways
HIGH 1 Publication of most significant flood risk assets in Westminster
HIGH 2 Designation of significant flood risk assets to ensure that they are maintained.
HIGH 3 Manage and Maintain drainage assets
LFRMS 2: Tackling flood risk through planning and development
DEV 1: Provide Technical advice and promote SUDS through planning and development
DEV 2:Develop flood risk policy to manage, mitigate and adapt to flood risk
DEV 3 Review and Revise Strategic Flood Risk Assessment, as new data becomes available, or on a 6 yearly cycle, whichever is more appropriate.
DEV 4: Review and revise Local Flood Risk Management Strategy and Flood Risk Management Plan on a 6 yearly cycle.
DEV 5- Use LFRMS to inform development of Local and Neighbourhood and development plans, drainage management and maintenance plans and programming: contingency plans and asset management plans
LFRMS 3 Tackling flood risk through Raising Awareness
AWARE 1 Modelling Surface Water Flood Risk
AWARE 2 Prepare Flood Risk Awareness Communications Plan
AWARE 3 Publish significant flood incident reports
AWARE 4 Publish significant flood risk asset register.
LFRMS 4 Tackling flood risk through Partnership working
PART 1: Work in partnership with other flood risk management authorities, stakeholders and relevant departments to address flood when it happens, and ensure contingency plans is appropriate.
PART 2: Work with Thames Water and other key stakeholders to mitigate and manage flood risk from surface water and manhole surcharge in Westminster,
Part 3 :Organise, attend and participate in flood risk management meetings such as Drain London/LoDeg, London Central North Flood Risk Group and Westminster City Council’s flood risk management group
LFRMS 5:Flood Risk Management and Maintenance
RISK 1: Seek opportunities for Sustainable Drainage Systems across the city
RISK 2: Implementation of LFRMS and action plan
RISK 3 Identify and prioritise programme of flood risk management projects and funding for 2015-2020 and provide multiple benefits in terms of biodiversity, amenity, health and wellbeing.

Preliminary Assessment (WFD Step 3)

Step 3 of the assessment process identifies which of the draft actions (of those which could physicallyaffect the environment) are unlikely to have any impact onany WFD objectives and which could have an impact and therefore need to be taken forward for further assessment i.e. Step 4 design and options appraisal and Step 5 detailed impact assessment.

If it is determined that no deterioration will occur across any of the WFDquality elements as a result of the draft actions and that they will not prevent any water bodyfrom meeting its status or potential objectives, then no further WFD compliance assessmentis required.

Figure 3summarises the preliminary assessment process; for each action the process considers:

  • The potential for hydromorphological, physio-chemical or chemical effects on any water body;
  • Possible cumulative effects of a number of actions which would be inconsequential alone but may be significant in combination;
  • Whether the action is associated with any habitats that are particularly sensitive or are critical to the individual biological quality elements (e.g. a fish spawning area within a river water body);
  • If the water body / bodies in question is / are not already at good ecological status or potential, the potential for the actions to interfere with measures that are necessary to achieve good status / potential; (these measures are detailed in the RBMP).

Assessment of each of the draft actions is presented following Figure 3, and the findings summarised in Table 4.